These functions weren't called anyway since 5e8f568f64 commit where Benchmark protocol requirement for this function acquired Double return type. In any event, skipping of warmup iteration is better controlled by the corresponding option of "benchmark run" command.
According to LZMA specification this property is ignored by the reference implementation. In addition, specification suggests that other LZMA decoders should also ignore it. We weren't using this property for anything anyway, so its removal does not really change anything, except for better compliance with LZMA specification.
In addition, range decoder initialization error is now thrown in accordance with reference implementation.
First, write(unsignedNumber:) is better than write(number:) when the argument is already UInt, since it does one fewer precondition check and does not do additional integer conversion. Secondly, using write(number:) to write one bit was very inefficient.
This allowed to rewrite implementation in a much clearer way. One user-visible change, however, is that NEW/BASE is now always printed with an index even if there is only one (implementation complexity to accommodate empty index is not worth it).
Ultimately, it turned out that the approach of the old save file format of separating runs metadatas and results only leads to super complicated code. Unfortunately, it didn't help with append-updates to save files (they are still loaded fully, their content is modified in memory, and the actual file is then overwritten).
This was caused by incorrectly assuming that out window (dictionary) always starts at 0 index. This is not correct in the case of LZMA2 where dictionary may have been reset, but the out window is technically not an empty array.
Previosuly, repeated calls of read() or process() after reaching EOF would result in DataError.truncated being thrown. This behavior caused issues when there was no EOF marker in the TAR container.
Timofey Solomko